Non-Iron Oxygen Scavengers in Food Packaging: Mechanisms, Applications, and the Shift Towards Green Alternatives

Abstract

Oxygen exposure in packaged foods accelerates oxidative spoilage, microbial growth, and sensory degradation. While iron-based oxygen scavengers are widely used, concerns over safety, recyclability, and consumer perception have led to interest in non-iron alternatives. This review critically examines recent developments in natural and synthetic non-iron oxygen scavengers, including antioxidants (ascorbic acid, tocopherol), unsaturated hydrocarbons (polybutadiene), enzymes (glucose oxidase, catalase), microorganisms, and polyphenolic plant extracts (gallic acid, catechu). Reported oxygen scavenging capacities range from 6.44 cm³ O₂/g (α-tocopherol) to 200 mL O₂/g (polybutadiene), with activation triggered by moisture, UV, or pH. Plant-based systems such as catechu-calcium carbonate combinations offer biodegradable, edible alternatives suitable for moisture-rich foods. The review also discusses activation mechanisms, integration into polymer matrices, regulatory considerations, and challenges in commercialization. These systems offer safer and more sustainable options for extending shelf life and preserving food quality in active packaging applications, with emerging trends including biodegradable films, multifunctional packaging, and smart indicators.